FED variant #2 - "Triggered on input"

A project log for Feeding Experimentation Device (FED) 2.0

FED measures food intake in mice. It is battery powered and designed to be used in rodent colony caging.

lex-kravitzLex Kravitz 06/05/2018 at 01:060 Comments

A colleague asked for a small modification to FED, such that in addition to the output pulse on the BNC connector, it would have a 2nd BNC which it would use as an input.  This input would trigger FED to dispense, but we would still monitor the pellet well and only dispense if it was empty.  This allows FED to act like a "smart" pellet dispenser in operant tasks, such that it not only dispenses a pellet, but detects when it is removed.  

Feeling a bit lazy, I just drilled a hole in a regular FED instead of reprinting a new base with 2 holes for BNC connectors.  I connected the new BNC to digital pin 5 on the Feather (remember when we put extra 90 degree headers there?), and wrote an updated code to allow for this behavior.  Updated code is available in the files area, to use simply connect the input BNC to pin 5 and ground, and flash the updated code.